This invention generally relates to an improved extracorporeal method and system for treating diseases and conditions resulting from or dependent upon deficiencies in the immune response system, and particularly for treating cancer and other neoplastic tissue in mammals by reducing the levels of immunosuppressive components in the blood.
It is widely recognized that the cell mediated immune system will, under normal circumstances, attack and destroy cancer cells and other neoplastic tissue. However, the cell mediated immune response is sometimes suppressed or blocked by one or more factors and when this dysfunction or dysregulation occurs the disease or condition (e.g., pregnancy) can develop and progress relatively unimpeded.
The nature and operational characteristics of the factor or factors which block or suppress the cell mediated immune system are for the most part unknown. Research has shown that these modulating factors exist in serum and that by removing these factors the serum will again allow a normal immune response.
Much of the work to date relating to the immunosuppressive activities of the blocking factors has been in vitro testing of cancer cell interactions with autologous lymphocytes. While the cytotoxic effects on cancer cells which have been incubated in serum treated in various ways to reduce the effects of the blocking agents has shown that cancer patients do have a lymphocyte population that can recognize and destroy cancer cells, there has been little or no progress in the development of treatment procedures for patients with immune deficiency diseases by any of the treatments used in such research.
One attempt to extracorporeally treat a patient's blood to mitigate the effects of an immune deficiency is found in European Patent Application No. 79,2211. In the process described in this patent application, blood is removed from a cancer patient and subjected to plasmaphoresis to separate plasma from the blood cells and then the plasma is perfused over a charcoal bed which has been coated with immobilized protein A. The plasma so treated is then remixed with the blood cells and returned to the patient. Significant immune response was noted against cancer tissue in these patients. Because the plasmaphoresis process used to separate the blood cells from the plasma has a serious impact on the platelet level in the blood, this process could not be considered for widespread use in a variety of patients, particularly those in the serious conditions of advanced cancers and in autoimmune diseases. Furthermore, the processing steps of first separating the blood into a fraction of packed cells, a bulky coat layer and a fraction of plasma by plasmaphoresis and then treating the plasma in the manner described are not very attractive for clinical use.
Thus, notwithstanding all the outstanding work which has been done on immunosuppressive effects of blocking factors, particularly the work in the last 15 to 20 years, there still remains the obvious and widespread need of a safe, simple and inexpensive method and system which can treat or control diseases or conditions resulting from immune system disregulation in a clinical setting.
The present invention was developed in response to these well known and widespread needs and satisfies the many requirements thereof.